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Commitments and Contingencies (Guarantees and Letters of Credit) (Details) $ in Millions, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 CAD ($) | Dec. 31, 2017 CAD ($) | Dec. 31, 2018 USD ($)
Nova Scotia Power Inc. [Member] | Jointly Owned Electricity Generation Plant [Member] |  |  |
Guarantor Obligations [Line Items] |  |  |
Utilities Operating Expense, Maintenance and Operations | $ 2 | $ 3 |
Utilities Operating Expense, Purchased Power | 19 | $ 18 |
Payment Guarantee [Member] | SeaCoast Gas Transmission LLC [Member] |  |  |
Guarantor Obligations [Line Items] |  |  |
Guaranty Liabilities |  |  | $ 45
Letters of Credit Outstanding, Amount |  |  | 27
Pension plan [Member] | Nova Scotia Power Inc. [Member] |  |  |
Guarantor Obligations [Line Items] |  |  |
Letters of Credit Outstanding, Amount | $ 49 |  |
Reinsurance agreements [Member] | Emera Reinsurance Limited [Member] |  |  |
Guarantor Obligations [Line Items] |  |  |
Letters of Credit Outstanding, Amount |  |  | 6
Surety bonds |  |  |
Guarantor Obligations [Line Items] |  |  |
Letters of Credit Outstanding, Amount |  |  | $ 67

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- Definition This item represents a non-contingent liability for the fair value of an obligation to stand ready to perform over the term of a guaranty issued in the event that specified triggering events or conditions occur. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 25 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82913062&loc=d3e11049-110243 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.15) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 25 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=82913062&loc=d3e11019-110243 + Details
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